The present invention relates to an orange toner for developing electrostatic charge images.
In recent years, with remarkable development of digital image input devices, such as a high performance of digital cameras and high image quality of liquid crystal display, printed matters have been also required to expand color reproduction range. For such requirements, color materials have been sought to have higher color purity and the chemical constitutions of color materials have been improved. However, as compared with liquid crystal displays which have a light source in itself and represents colors by the additive color process, since printed matters represent colors by the subtractive color process, it has been difficult to supplement the gaps.
Generally, in color image forming methods by an electrophotographying system, color reproduction is performed with combinations of three color toners such as a yellow toner, a magenta toner, and a cyan toner. Therefore, there are specific problems that the color reproducibility in the high lightness region of secondary colors becomes poor. Concretely, for example, in the case where orange is reproduced, a toner image by a yellow toner and a toner image by a magenta toner are superimposed. Accordingly, saturation and lightness decrease so that it is difficult to obtain an orange image with high saturation and high lightness.
Then, toner has been proposed so as to expand its color reproduction range and to improve hue by including a fluorescence color material as a colorant (for example, refer to Japanese Unexamined Patent Publication No. 2000-181170, Official report).